1. Field of the Invention
The present invention relates to the field of box-making machines, Specifically, the present invention provides an apparatus for bending a sending box sheet or a sending box sheet blank along a fold formed at a predetermined position in the box sheet.
2. Description of the Related Art
Conventionally, an apparatus for bending a sending box sheet along a fold formed at a predetermined position in the box sheet comprises a hook, which can hang a tip of the sending box sheet, and a sensor which can detect said tip of the sending box sheet. Accordingly, said sensor can detect said tip of the sending box sheet, and said hook can bend the sending box sheet along a first fold by holding a tip of the sending box sheet.
Namely, as shown in FIG. 8(a), in a typical device for bending a sending box sheet along a fold, a hook 5 is provided. The hook 5 is pressed by a spring for an opposite direction (left direction of FIG. 8(a)) of a sending direction of a box sheet 1 and can move the sending direction (right direction of FIG. 8 (a)) of the box sheet 1. A tip 5a of the hook 5 is positioned on a sending route of the box sheet. Therefore, when the box sheet 1 is sent, the tip 5a of the hook 5 holds the tip 1a of the sending box sheet 1.
When the box sheet is further sent, the hook 5 moves in the sending direction of the sending box sheet 1. Then, as shown in FIG. 8(b), the box sheet I is bent along a first fold by a force of the spring. The box sheet is further sent, as shown in FIG. 8(c), and because the tip 5a of the hook 5 is left of the tip 1a of the box sheet 1, the hook 5 is restored by force of the restitution of the spring, and then the bending box sheet 1 is sent frontwards.
The typical device for bending a sending box sheet along a fold being thus described, it is possible to bend the box sheet automatically during the process of sending the box sheet. However, because the tip of the hook is on a sending route of the box sheet, when the hook is restored, the tip of the hook hits on a face of the sending box sheet, thereby making a noise. In cases where the box sheet is sent at high speed, the noise increases. Furthermore, certain countries regulate the importation of a device which makes noise beyond a prescribed level.